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本文通过比较2011年分离培养的1株季节性甲型H1N1流行性感冒(简称流感)病毒(A/Shanghai/1167/2011(H1N1))与历年季节性甲型H1N1流感病毒的血凝素(HA)基因,追溯该病毒的基因变异与来源,探讨该毒株的出现对流感防控工作的意义。采用反转录-聚合酶链反应(RT-PCR)方法扩增病毒的HA和神经氨酸酶(NA)片段,并进行测序;应用分子生物学软件对获得的序列进行分析,绘制基因进化树;同时,通过血凝抑制试验检测2011年下半年健康人群中该流感病毒的抗体水平。结果显示,A/Shanghai/1167/2011(H1N1)的HA基因序列与世界卫生组织(WHO)2007～2008年季节性甲型H1N1流感病毒疫苗株A/Brisbane/59/2007(H1N1)最接近,同源性达99.2%,与新型甲型H1N1流感病毒A/California/07/2009疫苗株同源性仅为72.4%。其HA基因裂解位点为PSIQSR↓GLF,尚未出现高致病性的分子特征。HA片段共编码557个氨基酸,有9个潜在的糖基化位点,序列与2009年前WHO疫苗株A/NewCaledonia/20/1999(H1N1)、A/SolomonIslands/3/2006(H1N1)和/Brisbane/59/2007(H1N1)相比,分别有15、12和4处不同,这些差异分布在Sa、Sb、Ca1、Ca2、Cb5个抗原决定簇的氨基酸差异分别有5、5和2处。该毒株在健康人群血清的抗体阳性率为34.33%,几何平均效价(GMT)为10.38。A/Shanghai/1167/2011(H1N1)是2011年出现在上海地区的一个季节性甲型H1N1流感病毒毒株,其抗原变异与既往季节性甲型H1N1流感病毒相比不大,但在以A(H1N1)pdm09为主要流行株的年份检测到散在发生的既往季节性甲型H1N1流感病毒毒株应当引起重视,其在人群中的抗体水平较低,易引起流行,需要提高对类流感人群中此种毒株的持续监测。
In this paper, we compared the genetic diversity of a seasonal influenza A (H1N1) virus (A / Shanghai / 1167/2011 (H1N1)) isolated in 2011 with that of the seasonal influenza A (H1N1) ) Gene, tracing the gene mutation and source of the virus, and discussing the significance of the emergence of the strain on the prevention and control of influenza. The HA and neuraminidase (NA) fragments of the virus were amplified by reverse transcription-polymerase chain reaction (RT-PCR) and sequenced. The molecular phylogenetic tree was used to analyze the obtained sequences and the phylogenetic tree ; Meanwhile, the antibody level of the influenza virus in healthy population in the second half of 2011 was tested by the hemagglutination inhibition test. The results showed that the HA gene sequence of A / Shanghai / 1167/2011 (H1N1) was the closest to the WHO A / Brisbane / 59/2007 (H1N1) vaccine from 2007 to 2008 in the World Health Organization (WHO) The homology was 99.2% with only 72.4% homology with the new A / California / 07/2009 vaccine. The cleavage site of HA gene is PSIQSR ↓ GLF, yet no highly pathogenic molecular features have been reported yet. The HA fragment encodes a total of 557 amino acids and has 9 potential glycosylation sites. The sequence matches with the 2009 vaccine strains A / NewCaledonia / 20/1999 (H1N1), A / Solomon Islands / 3/2006 Brisbane / 59/2007 (H1N1), 15, 12 and 4, respectively. The differences were found in 5, 5 and 2 amino acid residues of Sa, Sb, Ca1, Ca2 and Cb epitopes respectively. The positive rate of the antibody in the serum of the healthy people was 34.33% and the geometric mean titer (GMT) was 10.38. A / Shanghai / 1167/2011 (H1N1) is a seasonal influenza A (H1N1) virus strain that appeared in Shanghai in 2011. Its antigenic variation is not significant compared with the previous seasonal influenza A (H1N1) pdm09 as the major epidemic strains of the past seasonal influenza A (H1N1) virus strains should be taken seriously, its antibody level in the population is low, easy to cause the epidemic, the need to improve the influenza-like population Continuous monitoring of such strains.